Executive brief
A vulnerability was identified in the Linux kernel's Microchip QSPI driver where the system incorrectly attempted to transmit data during read-only operations. This could lead to the communication interface becoming unresponsive or 'bricked' during specific data transfers. While primarily a stability issue, it could impact the availability of hardware components relying on this driver.
Technical details
A logic error exists in the 'spi-microchip-core-qspi.c' driver within the 'mchp_coreqspi_transfer_one' function. The driver was attempting to perform a write-read operation even during emulated read-only dual or quad SPI transfers. Because QSPI lacks a dedicated master-out line (MOSI) like standard SPI, transmitting 'garbage' data during these cycles can cause the hardware core to lose track of the transfer state or corrupt the bus, effectively bricking the transfer. The fix introduces a check for dual/quad mode to ensure only a read operation is triggered. Patches have been applied to multiple stable branches of the Linux kernel.
Affected products
- Linux Linux Kernel All versions prior to the fix in May 2026
Timeline
- 2026-04-30: other: Patch authored by Conor Dooley
- 2026-05-28: disclosed: Vulnerability published in NVD and kernel logs